how can you tell between an 04 yfz motor and an 05 yfz motor????

[quads_only]

how can you tell the difference between an 04 and an 05 motor? does the numbers on the motor mean anything? I think the yfz that my friend bought is an 05 frame with an 04 motor and stuff on it. it has the steel brake pedal and shifter. but I cant figure out the motor. any help would be great thanks.

[novadave]

04 and 05 i beleive are the same . 06 is when they made changes like the shifters.

[ROC0999]

the tenth digit in the vin # will tell you what year it is .

[Chillinthemost]

The 04 will have a decompression plug in the front of the head, it is the only year that had it. 06 got the better swingarm, aluminum pedals,etc.